The present invention relates to a peripheral connecting region having two sheets which are connected to each other such that they cannot be displaced relative to each other. The invention also relates to a method for providing such a peripheral connecting region with a peripheral connection.
In the car industry, it is frequently necessary to connect body sheets to each other in their peripheral regions. Such connections have hitherto been carried out mainly by means of welding; it is possible for different welding methods to be used.
A welding connection of two sheets is always a problem if the sheets are of materials which are not easy to weld or which cannot be welded at all. This is the case if, for example, high-strength steels or different materials, such as aluminium or plastic, are to be connected to one another. Connection of galvanized sheets by means of welding is also a problem. In this case, other joining methods, such as riveting, are also difficult to carry out.
One object of the invention is the object of proposing a peripheral connecting region of two sheets and a method for producing such a connecting region in which, even when welding is used for materials which are no longer accessible or which can only be accessed with difficulty, a robust, simple to produce and permanent connection of the two sheets is ensured.
This object is achieved according to the invention by way of a peripheral connecting region configured such that it includes two overlapping sheet flanges and a strip-shaped fastening element, which encloses an outer contour of the flanges and rests with some sections of its inner side on mutually remote surfaces of the flanges, by which the sheets are connected. This object is also achieved according to the invention by way of a peripheral connection method in which at least one of two sheets is provided with a hole in a connecting region, a strip-shaped fastening element is folded around an outer contour of sheet flanges in such a manner that it encloses the outer contour and rests with some sections of its inner side on mutually remote surfaces of the sheet flanges, and a deformation region of the fastening element is pressed into the hole and covers the hole. Thus, a connecting region in which the sheets are connected by a strip-shaped fastening element, which encloses the outer contour of the flanges and rests with some sections of its inner side on the mutually remote surfaces of the two flanges, is proposed.
Such a connecting region offers advantages over a welding connection because demands do not have to be placed on the material of the sheets. The fastening element has to be of an extendable material, since it has to be folded around the two flanges. Any conventional steel material is suitable here. Sheets made from different, non-steel or high-strength materials can be connected to one another in this manner.
An adhesive is expediently additionally provided between the inner side of the fastening element and those regions of the flanges which lie opposite the inner side. The strength of the connection can thereby be increased. Furthermore, a leakproof connection can thus be achieved.
At least one flange is advantageously provided with a hole in a region, which is remote from the sheet edge, on the surface, which is remote from the second flange, and a deformation region of the fastening element is pressed into the hole and covers the hole. The fastening element is thereby secured against becoming detached in the direction parallel to the periphery of the flanges.
In a further advantageous embodiment of the connecting region, the flanges have, in the connecting region, overlapping through-holes within which the deformation region of the fastening element is connected non-releasably to an opposite region of the fastening element. In this manner, high connecting region strength is achieved in little structural space.
In a further advantageous embodiment, the flanges protrude from each other at an acute angle in a peripheral region of the connecting region, which peripheral region faces the sheet edge. As a result, the connecting region has a V profile. In this case, at least some sections of the inner side of the fastening element rest in a sheet-like manner in the wedge-shaped cavity formed by the limbs of the flanges. This ensures that the fastening element is connected to the flanges in such a manner that it cannot be detached from the flanges in a direction perpendicular with respect to the periphery of the flanges.
As an alternative or in addition to the holes, the flanges may be provided in the peripheral region with a wavy contour in the longitudinal direction or with a peripheral contour on the periphery of the flanges. This way of securing against the connection becoming detached offers an additional advantage in that stamping of the sheets can be undertaken even before the connecting region is produced and, after the fastening element has been folded up, no further working steps are necessary.
A method according to the invention for providing a peripheral connection of two sheets includes, first of all, providing at least one of the two sheets with a hole in a connecting region. A strip-shaped fastening element is then folded around the outer contour of two flanges in such a manner that it encloses the outer contour and rests with some sections of its inner side on mutually remote surfaces of the two flanges. Finally, a deformation region of the fastening element is pressed into the hole and covers the hole.
In one advantageous embodiment, through-holes are provided as the holes in the sheets. Within the holes, the deformation region of the fastening element is connected non-releasably to an opposite region of the fastening element. The connection thereby obtains high strength.
The deformation region and opposite region of the fastening element are advantageously connected to each other by a rivet. This is a connecting method which can be carried out very simply and cost-effectively.
Furthermore, the deformation region and the opposite region of the fastening element can be connected to each other by means of joints passing through them. This makes it possible for the overlapping holes to be very small, since the joining tool is space-saving. Furthermore, only a little amount of space is required for connecting the sheets.
Furthermore, the deformation region and the opposite region of the fastening element can be connected to each other by means of spot welds. A spot welding method can be carried out very simply, cost-effectively, and without the use of additional components.
Further refinements and advantages of the invention are apparent from the description.
The invention is explained in greater detail with reference to two exemplary embodiments in the drawings.